Thoracic outlet syndrome, and what it means for Matt Harvey and the Mets

Matt Harvey's already-frustrating season has gotten much worse. In addition to being the subject of tabloid humor in spring training, enduring by far the worst season of his career statistically and landing on the disabled list on Wednesday with right shoulder discomfort, the Mets' one-time ace has now been diagnosed with, according to New York general manager Sandy Alderson, "symptoms consistent with thoracic outlet syndrome" and is considering season-ending surgery.

Against the Marlins at Citi Field on Monday, Harvey was peppered for 11 hits and six runs in 3 2/3 innings, the second consecutive start in which he failed to make it out of the fourth inning. According to ESPN's Adam Rubin, Mets manager Terry Collins said of the 27-year-old righty, "He came in the training room afterward and said, 'My shoulder is dead. My arm is dead. There's no energy there. I couldn't feel the ball.’" On Wednesday, Newsday reported that a team source had told the paper's David Lennon that the club suspected Harvey had thoracic outlet syndrome, and that the pitcher would be send to St. Louis on Thursday to consult with Dr. Robert Thompson, a vascular specialist who performed the TOS surgery for Cardinals pitcher Jaime Garcia in 2014.

Harvey is the second pitcher in recent days to be connected to thoracic outlet syndrome; just this week, the Twins' Phil Hughes underwent the procedure for TOS, which is caused by a compression of the nerves and/or blood vessels somewhere between the neck and the armpit. It's not uncommon for TOS to present itself as numbness or tingling in the fingers and hands, or fatigue or weakness that doesn't go away with physical therapy and rest. Pitchers tend to be vulnerable to it because of the way their arm muscles build up. The condition is generally remedied by the removal of a cervical rib, but there are a wide range of possibilities as to what comes next. Some pitchers who have had the surgery—including Kenny Rogers (2001), Matt Harrison ('09), Josh Beckett ('13) and Garcia—have recovered to fare well at the major league level. Rogers is perhaps the greatest success story, having made three straight All-Star teams from 2004 to '06 while helping the Tigers reach the World Series in the last of those years. Garcia returned in May of 2015 and posted a 2.43 ERA in 20 starts for the Cardinals that season.

Other pitchers—such as Jeremy Bonderman (2008), Noah Lowry ('09) and Chris Carpenter ('12)—were never the same after the procedure. Bonderman only had one more season in which he made more than 20 appearances, last pitching in the bigs in 2013; Lowry never threw another major league pitch; and Carpenter made six starts in the majors in late 2012, but his symptoms recurred the following spring and he made just two starts in the minors (none in the majors) before retiring later that year.

Recovery from TOS rib removal surgery is generally long. Alderson told reporters on Thursday that Harvey would require at least a fourth-month rehab if he has the operation, meaning that he wouldn't make it back this season. A nerve block injection could provide a temporary fix, but he would probably need surgery to correct the problem at some point.

This is just the latest turn in the ongoing saga about Harvey's health. He had Tommy John surgery and missed all of 2014, though at one point he made noise about wanting to return late in the year, an idea that the team had to publicly reject. When he returned last year, a long debate about a possible innings limit dogged Harvey and the team as New York advanced to the World Series. In Game 5, Harvey convinced Collins to let him pitch the ninth inning holding a 2–0 lead, only to allow the Royals back into a game they eventually won to clinch the championship. Finally, in late March of this season Harvey was treated for blood clots in his bladder.

Once the season started Harvey's performance was so poor that it led to speculation about whether he was fully healthy, and he nearly lost his rotation spot in late May after his ERA climbed to 6.08. He appeared to have settled down by posting a 2.27 ERA over his six starts from May 30 to June 28, the last of those a rain-shortened outing; he allowed just 35 base runners in 35 2/3 innings over that span without yielding a homer, and his average fastball velocity enjoyed a slight uptick.

It's that upside the Mets will sorely miss, even if Harvey's overall numbers in 92 2/3 innings aren't impressive. His 4.86 ERA and 7.4 strikeouts per nine represent career lows, though his peripherals haven't been all that bad; he owns a 3.50 FIP but a .359 batting average on balls in play. His average fastball velocity has been down roughly one mile per hour relative to last season, and he has struggled with his mechanics at times, most notably while pitching from the stretch. With men on base, batters have hit .354/.379/.537 against him.

Harvey's diagnosis comes in the wake of last week's revelation that fellow starters Steven Matz and Noah Syndergaard are pitching through bone spurs in their elbows; the former's is much more significant than the latter's, enough so that surgery looms as an option if he can't manage the discomfort the spurs are causing. Even with Harvey's difficulties, the Mets' staff is fourth in the league in ERA (3.40) and third in FIP (3.42), with Syndergaard, Bartolo Colon and Jacob deGrom each carrying an ERA below 3.00 and combining to deliver quality starts 71% of the time.

For now, Logan Verrett will take Harvey's spot in the rotation. The 26-year-old righty has a 4.01 ERA but a 5.57 FIP in 18 relief appearances and five starts totaling 49 1/3 innings. In April, he strung together a pair of scoreless six-inning starts, but in his three spot starts since then, he's allowed 14 runs in 11 2/3 innings. Any hopes that 26-year-old righthander Zack Wheeler, who has yet to pitch since undergoing 2014 Tommy John surgery, could take Harvey's spot have been dashed by setbacks; after a bout of nerve irritation in his elbow, he just resumed throwing off flat ground last week, and there's no timetable for his return.

All of that suggests that the Mets—who at 46–38 occupy the second NL wild-card spot and are four games behind the Nationals in the NL East—will be in the market for another rotation option as the Aug. 1 trade deadline approaches (the Twins' Ervin Santana and the Athletics' Sonny Gray are rumored to be among the prominent starters teams are eyeing). Finding one who can pitch as Harvey did at his best will be a tall order. Holding out hope that Harvey can eventually return to being the staff ace may be an even taller one.

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